Patents by Inventor Alexandre W. Walker

Alexandre W. Walker has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Publication number: 20230395735
    Abstract: An example semiconductor device includes: a first layer comprising a first semiconductor material; a second layer comprising a second semiconductor material; and an interface region disposed between the first layer and the second layer and corresponding to an expected depletion region of an interface between the first semiconductor material and the second semiconductor material, the interface region comprising a gradation from the first semiconductor material to the second semiconductor material; and wherein the interface region is configured to reduce Shockley-Read-Hall recombination in the semiconductor device.
    Type: Application
    Filed: October 19, 2021
    Publication date: December 7, 2023
    Inventor: Alexandre W. Walker
  • Publication number: 20230327041
    Abstract: A mesa-type avalanche photodiode comprising a first mesa of n-type material, a second mesa having an active region, and a third mesa of p-type material, wherein the second mesa includes a p-type sidewall formed by Zn diffusion for suppressing sidewall leakage current.
    Type: Application
    Filed: August 27, 2021
    Publication date: October 12, 2023
    Inventors: Oliver James PITTS, Alexandre W. WALKER
  • Publication number: 20230178644
    Abstract: A semiconductor high electron mobility transistor (HEMT)-based device configured to detect ionizing radiation, wherein the device comprises: a substrate; a nucleation layer formed on the substrate; a gallium nitride (GaN) buffer layer arranged on the nucleation layer; a GaN channel layer arranged on the GaN buffer layer; an aluminum nitride (A1N) spacer layer arranged on the GaN channel layer; a barrier layer arranged on the A1N spacer layer; a GaN cap layer arranged on the barrier layer; an electrically insulating silicon nitride (SiNx) passivation layer arranged on the GaN cap layer; a source, a drain and a gate, wherein the source and the drain are formed on the GaN cap layer; wherein charge carriers generated by the radiation in the underlying GaN layers are collected in the GaN channel layer and multiplied by impact ionization by a high electric field at the gate edge facing the drain contact.
    Type: Application
    Filed: April 27, 2021
    Publication date: June 8, 2023
    Inventors: Jean-Paul NOËL, Ryan GRIFFIN, Alexandre W. WALKER
  • Publication number: 20230099143
    Abstract: An example short-wave infrared imaging device includes: a detector to detect light representing an object to be imaged, the detector comprising a semiconductor wafer divided into an array of detector cells; and an image processor coupled to the detector to generate image data based on the reflected light detected at the detector; and wherein each detector cell comprises: a detection region of the semiconductor wafer; a dopant doped into the wafer in a sub-cell pattern having at least two spaced apart doped regions, the dopant to generate a signal based on light received in the detection region of the detector cell; a metal contact joining the at least two doped regions; and a signal processing circuit coupled to the metal contact to transmit the signal to the image processor.
    Type: Application
    Filed: March 19, 2021
    Publication date: March 30, 2023
    Inventors: Alexandre W. Walker, Philip Waldron